The invention relates to a semiconductor device with a semiconductor body comprising a semiconductor element with connection points, which semiconductor element adjoins a surface of the semiconductor body and is laterally insulated and surrounded by a first depression in the surface, which depression is provided with a wall and a bottom, while the surface of the semiconductor body and the wall and the bottom of the depression are covered with an insulating layer, the connection points being provided in the insulating layer on the surface of the semiconductor body, and being connected to conductor tracks which connect the connection points across a wall to connection surfaces belonging to the connection points and situated on a bottom.
Such a device is also known as a semiconductor device with mesa insulation. The upper portion of the semiconductor body adjoining the surface and surrounded by the depression in fact forms a mesa with an upper side, a wall, and a bottom next to the mesa. The semiconductor element is possibly present partly in the mesa. The connection points of the semiconductor element present on the upper side of the mesa form connection points for, for example, base, emitter, collector, source, drain, anode or cathode zones or for gate electrodes of switching elements such as, for example, transistors, diodes, or thyristors. The semiconductor element may comprise several such switching elements and also resistor zones and capacitors. In general, the connection points are formed by contact holes in the insulating layer which covers the upper side of the mesa. Through these contact holes, semiconductor or conductor regions in the mesa are connected to the conductor tracks. The connection points are electrically connected by means of the conductor tracks to connection surfaces or bond pads, which are usually made of the same material as the conductor track. In general, each connection point of the semiconductor element has its own bond pad. Thus, for example, an emitter connection point will be connected to an emitter bond pad. The bond pads serve to make electrical contact with connection legs of a lead frame, for example, through bond wires or contact elevations, so-called bumps. The bond pads are comparatively large in order to facilitate such a contact. The bond pads accordingly are present next to the mesa on the bottom of the depression and not directly on the surface of the semiconductor body on top of the mesa. The placement of comparatively large bond pads on the upper side of the mesa, i.e. on the semiconductor element, would lead to an enlargement of the mesa, which leads to comparatively high capacitances in the semiconductor element, whereby the semiconductor element is not suitable, for example, for high frequencies.
Patent Abstracts of Japan vol. 16, no. 330 [4-199719]discloses a device of the kind mentioned in the opening paragraph with a high electron mobility transistor (HEMT) as a semiconductor element in a mesa. Connection points for the gate, source, and drain of the transistor are present on the surface of the semiconductor body, on the upper side of the mesa. These connection points are connected to bond pads on the bottom of the depression through conductor tracks, i.e. next to the mesa.
In practice, semiconductor devices with ever smaller details are manufactured owing to an increasing miniaturization. The known semiconductor device has the disadvantage that the manufacture of miniaturized known semiconductor bodies leads to rejects owing to short-circuits between bond pads of the semiconductor element.